材料和内边界约束对薄壁圆管轴向压缩吸能特性的影响研究

To obtain energy-absorbing structures with best efficiency under the constraints of space and mass, the energy absorption behaviors of thin-walled circular tubes made of 45# steel, 6061-T6 aluminum alloy and TC4 titanium alloy under axial compression were analyzed by numerical method. The effects of material properties, structural parameters and inner boundary constraints on the deformation mode and energy absorption characteristics of thin-walled circular tubes were obtained. The results show that the deformation of the tube with good ductility is progressive collapse, while the deformation of the tubes with bad ductility is axial splitting or progressive fracture; the specific energy absorption of the structures increases with the increase of the thickness/diameter ratio, and the specific energy absorption of titanium alloy thin-walled tube is the best, but there is a large peak load; when the inner diameter, height and mass of the tubes are the same, the energy absorption of titanium alloy tube is 1.1 and 3.1 times that of aluminum alloy tube and steel tube, respectively. For thin-walled tubes with progressive collapse, the introduction of the inner boundary constraint can improve the energy absorption characteristics of the thin-walled circular tubes, the specific energy absorption can be improved by about 13% under the inner boundary constraint.